Powerbook HD capacity

macrumors newbie

Hi all, just received my new 15" powerbook 1.5 yesterday. Everything about it is flawless but I do have 1 question...

I did a BTO for the 80 GB 5400 HD. When I "get info" on the hard drive the capacity is shown as 74.4 GB. (available = 66.54) My previous computer had a 10 GB HD so this isn't a deal-breaker.

I realize there is some variability in the actual capacity but I am thinking that getting 5.6 GB LESS than what I ordered is kind of a big deal to me. Anyone else have a similar situation and/or do you think I would be justified in calling Apple to complain a bit?

Moderator emeritus

You should read the small print a bit better. You Mac reports disk size "correctly", i.e. 1Kb = 1024 bytes, 1Mb = 1024Kb, 1Gb=1024 Mb. Hard drive manufactures (and therefore Apple as well) report disk size "incorrectly", i.e. 1Kb =1000 bytes, 1Mb = 1000 Kb, 1Gb =1000 Mb. This means that you are missing 48576 bytes per Mb (just over 47 "real" Kb). Over the course of an 80Gb disk this soon mounts up to the difference you see. This is all noted in the small print at the bottom of the tech specs page.

thread startermacrumors newbie

You should read the small print a bit better. You Mac reports disk size "correctly", i.e. 1Kb = 1024 bytes, 1Mb = 1024Kb, 1Gb=1024 Mb. Hard drive manufactures (and therefore Apple as well) report disk size "incorrectly", i.e. 1Kb =1000 bytes, 1Mb = 1000 Kb, 1Gb =1000 Mb. This means that you are missing 48576 bytes per Mb (just over 47 "real" Kb). Over the course of an 80Gb disk this soon mounts up to the difference you see. This is all noted in the small print at the bottom of the tech specs page.

Click to expand...

Thanks robbieduncan! That answers my question perfectly. Now I can officially say I have 0 complaints with a fantastic new computer. I appreciate your response.

macrumors 6502a

You should read the small print a bit better. You Mac reports disk size "correctly", i.e. 1Kb = 1024 bytes, 1Mb = 1024Kb, 1Gb=1024 Mb. Hard drive manufactures (and therefore Apple as well) report disk size "incorrectly", i.e. 1Kb =1000 bytes, 1Mb = 1000 Kb, 1Gb =1000 Mb. This means that you are missing 48576 bytes per Mb (just over 47 "real" Kb). Over the course of an 80Gb disk this soon mounts up to the difference you see. This is all noted in the small print at the bottom of the tech specs page.

Click to expand...

I would argue the opposite. Apple is reporting your HD size correctly. 1GB=1 billion Bytes. That's how the metric system works. Your HD however uses another calculation for GB. Check this out:

It is pretty misleading that Apple sells a computer with a listed GB when it knows its OS uses another calculation. But Apple's number is actually correct.

Click to expand...

I agree that the metric system is base 10. Unfortunatly a computer is base 2. Computer memory and disk sizes are not metric! For example a byte is 8 bits. If you want to claim that the drive manufacturers are correct you need to be metric all the way down. They are metric down to the byte, then switch to the correct measurement. i.e. a drive manufacturer says there are 8000 bits in Kb, the "normal" definition says there are 8192.

I can point to any number of definitions of Kb as 1024 bytes: for example.

macrumors 6502a

I agree that the metric system is base 10. Unfortunatly a computer is base 2. Computer memory and disk sizes are not metric! For example a byte is 8 bits. If you want to claim that the drive manufacturers are correct you need to be metric all the way down. They are metric down to the byte, then switch to the correct measurement. i.e. a drive manufacturer says there are 8000 bits in Kb, the "normal" definition says there are 8192.

I can point to any number of definitions of Kb as 1024 bytes: for example.

Click to expand...

Each side can point to definitions online. But from a historical perspective "kilo" has always meant 1000. The metric system has been around longer than computers. That's why new standard definitions were created

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